TheIronRuler said:
technically speaking, music is objective.
If you look at the basic form of it without all of the bling, you'll learn that it is objective.
The first thing you learn in the subject of harmony is the Intervals that create Chords. These Intervals are divided into two groups - Cossonant and Dissonant. Cossonant are nice to hear while Dissonant usually sounds like two cats trying to kill each other.
If you string them together in the best way humanly possible (with other supporting roles, themes and rythem) you have the greatest music ever created.
...and then there will still be those folks out there who think that it sounds like rubbish.
And anybody who tells them that they are wrong for that thought is an idiot.
Not saying that I completely disagree with you. Actually I believe it pays to be informed, in both musical theory, the history of the music you want to make and where that history has led to. To clarify on that last bit, I believe musical genres and the history of those genres are like a conversation. One musician says "this" with this piece of music, another "responds" by taking that first piece of music as inspiration in some way and so on. Some people that take part in this conversation will be ignored, some will grab other's attention. If I want to make good, relevant rock and roll (wide net I know), I'd do myself well to view this "conversation" closely from the beginning up to it's current point, otherwise I'd be that asshole jumping into a conversation in the middle without knowing what the hell I'm talking about, if that makes a lick of sense.
So yeah, I don't think it's possible to make objectively "better" music than any other music, I DO think it's possible however to make music that is more... "well informed" one might say.